End stage renal disease (ESRD) is an irreversible condition of kidney failure which results in death without medical intervention. The current standard (i.e., most common) U.S. medical care for ESRD is to replace kidney function with repeated extracorporeal blood processing called hemodialysis (HD). ESRD affects more than one million people world-wide and is increasing. Around 1963, long term HD treatments became possible with the introduction of the “Scribner Shunt”, which enables repeated access to a patient's central blood supply. Doctors experimented with time and frequency of HD and, by the 1970s, many doctors were using 3 treatments per week, with a treatment time of approximately 5 hours (or longer) per treatment. Although it was believed that a patient's well-being depended on limiting toxin exposure, safe values for such exposure were never elucidated.
In the 1980s, a mathematical relationship called “Kt/V” was derived by Dr. Gotch, which may be used to quantify toxin removal during HD treatment. Blood urea was selected as a representative biochemical marker for toxins, since blood urea was removed during HD and is easy measure (although blood urea itself is not a toxin). (Gotch F A, Sargent J A. A mechanistic analysis of the National Cooperative Dialysis Study (NCDS) Kidney Int 1985; 28:526-534) Trials comparing clinical outcomes to Kt/V led to agreed Kt/V levels for defining adequate treatment. Kt/V is a number calculated for each patient from the urea clearance characteristics of their HD dialyzer (K), the dialysis treatment time (t) and volume of blood treated (V). Kt/V values became the key marker to quantify US HD treatment and to justify the standard of three HD sessions per week (National Kidney Foundation. KDOQI). Clinical Practice Guidelines and Clinical Practice Recommendations for 2006 Updates: Hemodialysis Adequacy. Am J Kidney Dis 2006; 48:S3-S90; Miller J E, Kovesdy C P, Nissenson A R, Mehrotra R, Streja E, Van Wyck D, Greenland S, Kalantar-Zadeh K. Association of hemodialysis treatment time and dose with mortality and the role of race and sex. Am J Kidney Dis 2010; 55:100-12)
Some doctors voiced misgivings that the Kt/V value was used as a comprehensive or determinative marker of HD performance; and therefore for measuring/evaluating patient health and quality of life. Adopting Kt/V criteria to determine “adequate” HD treatment for more than 2 decades has permitted poor patient outcomes to continue without meaningful improvements. Most patients are subject to frequent complications and poor quality of life, without rehabilitation, after beginning dialysis. Not surprisingly, many U.S. patients choose to stop HD and die.
Over time many studies have described deficiencies in Kt/V as an objective measure for achieving good health and quality of life. (Scribner, Oreopoulos. The Hemodialysis Product (HDP): A Better Index of Dialysis Adequacy than KT/V Dialysis and Transplantation 2002. 31:1) Standardized Kt/V values could be reached with regimes for most patients consisting of 3 hours of treatment administered 3 times per week. However, not all doctors agreed—some felt that longer HD sessions, and/or more frequent (i.e., daily) dialysis, would be better. Longer and more frequent dialysis is sometimes referred to as “intensive HD” (IHD). Over 2 decades IHD results show an array of improved patient outcomes including better cognitive and physical function, more restful sleep, increased appetite, less diet and fluid restrictions, increased physical activity and endurance, a reduction in drug consumption and patients reporting substantially better quality of life. (Parker T F, Glassock R J, Steinman T I. Conclusions, Consensus, and Directions for the Future. Clin J Am Soc Nephrol 2009; 4:S139-44; Chazot C, Jean G. The advantages and challenges of increasing the duration and frequency of maintenance dialysis sessions. Nat Clin Pract Nephrol 2009; 5:34-44; Pauly R P. Nocturnal home hemodialysis and short daily hemodialysis compared with kidney transplantation: emerging data in a new era. Adv Chronic Kidney Dis 2009; 16:169-72; Hanly P. Sleep disorders and home dialysis. Adv Chronic Kidney Dis 2009; 16:179-88/Chan C T. Cardiovascular effects of home intensive hemodialysis. Adv Chronic Kidney Dis 2009; 16:173-8; Johansen K L, Zhang R, Huang Y, Chen S C, Blagg C R, Goldfarb-Rumyantzev A S, Hoy C D, Lockridge R S Jr, Miller B W, Eggers P W, Kutner N G. Survival and hospitalization among patients using nocturnal and short daily compared to conventional hemodialysis: a USRDS study. Kidney Int 2009; 76:984-90; Pierratos A. Daily nocturnal hemodialysis—a paradigm shift worthy of disrupting current dialysis practice. Nat Clin Pract Nephrol 2008; 4:602-3; Chan C T, Notarius C F, Merlocco A C, Floras J. Improvement in exercise duration and capacity after conversion to nocturnal home haemodialysis. Nephrol Dial Transplant 2007; 23:3285-91; Kraus M, Burkart J, Hegeman R, Solomon R, Coplon N, Moran J. A comparison of center-based vs. home-based daily hemodialysis for patients with end-stage renal disease. Hemodial Int 2007; 11:468-77; Ayus J C, Achinger S G, Mizani M R, Chertow G M, Furmaga W, Lee S, Rodriguez F. Phosphorus balance and mineral metabolism with 3 hour daily hemodialysis. Kidney Int 2007; 71:336-42).
However, IHD performed in HD clinics imposes even greater hardship on patients than does the current treatment regimen of 3 sessions per week, each of approximately 3½ hours per session (i.e., the current HD standard treatment). IHD performed at home allows flexible scheduling, and even HD while sleeping, which is more appropriate for long term chronic therapy.
Two different IHD methods have shown superior suitability and benefit for home treatment: nocturnal HD, which is performed nearly daily during sleeping and at lower blood flow rates, and daily HD, with short duration treatment while relaxing (i.e., reading, watching TV, etc). Another potential IHD treatment could be HD performed with small, portable and fully contained HD machines (i.e., called “Wearable HD Machines”) which allow a patient to dialyze almost anywhere while engaging in many activities. These “Wearable HD Machines” are in development, with several patents and papers published. (Rastogi A, Nissenson A R. Technological Advances in Renal Replacement Therapy: Five Years and Beyond. Clin J Am Soc Nephrol 2009; 4:S132-6; Gura V, Macy A S, Beizai M, Ezon C, Golper T A. Technical Breakthroughs in the Wearable Artificial Kidney (WAK). Clin J Am Soc Nephrol 2009; 4:1441-8).
One U.S. company (NextStage) is producing HD machines for the home treatment and is used by about 6000 home patients. Patients receiving IHD consistently report better quality of life.
HD is an extracorporeal blood cleansing treatment comprising the withdrawal of blood in a continuous process, the passing of the blood through a dialysis machine to remove waste products (i.e., water and metabolic toxins), and the returning of the blood back to patient. In HD clinics, senior nurses perform the blood accessing (i.e., the coupling of the machine to the patient's blood supply via the conduit interface connection called “blood access”). These blood accesses are subject to frequent complications resulting in frequent hospitalization and death. A particularly harmful failure mode is a break in the return blood line, which may result in bleedout and death of the patient if the blood loss by the patient is not stopped within a few minutes. These events still occur in HD clinics with close proximity to patients and workers. (Sandroni S. Venous needle dislodgement during hemodialysis: An unresolved risk of catastrophic hemorrhage. Hemodial Int 2005; 9:102-3; Polaschegg H D. Venous needle dislodgement: the pitfalls of venous pressure measurement and possible alternatives, a review. J Ren Care 2010; 36:41-8; MAUDE (Manufacturer and User Facility Device Experience, published by the US Food and Drug Administration—FDA) reports 2006 No. 716890, 743749, 770460, 770507.
Home-based dialysis requires patient responsibility for performing treatment including accessing of the patient's own bloodstream. It is evident that self-dialysis presents higher risk to the patient, especially from needle dislodgement, e.g., from an AV Fistula (AVF), while the patient sleeping. (FDA Advisory—Brief Summary from the Gastroenterology and Urology Devices Panel. http://www.fda.gov/AdvisoryCommittees/CommitteesMeetingMaterials/Medical Devices/MedicalDevicesAdvisoryCommittee/Gastroenterology-UrologyDevicesPanel/ucm124734.htm; Hawley C M, Jeffries J, Nearhos J, Van Eps C. Complications of home hemodialysis. Hemodial Int 2008; 12:S21-5).
Patient surveys describe considerable fear since they are aware of and/or have personally experienced failures with current access options. Such surveys also describe a patient's sense of being stigmatized by the disfigurement necessitated by HD access. Furthermore, self-accessing, which allows for greater independence and self-reliance, is an important factor in achieving broad acceptance of home HD treatment. However, fundamental improvements have not yet occurred which would provide safer, more robust and less disfiguring accessing, and which patients may perform by themselves.
The present invention is a system which solves or improves upon the current state of the art in HD access and is especially suited for home HD.